There is a very slight risk of having a severe reaction to the tuberculin skin test, especially if you have had tuberculosis (TB). An allergic reaction can cause a lot of swelling and pain at the site.
Can a TB test cause a rash?
Injection site erythema or injection site rash (without induration) occurring within 12 hours of testing. These reactions do not indicate TB infection. Injection site hemorrhage and injection site hematoma up to three days after the administration of the test.
How do you know if a TB skin test is positive?
A skin test is the only way to tell if you have TB infection. The test is “positive” if a bump about the size of a pencil eraser or bigger appears on your arm. This bump means you probably have TB infection. Other tests can show if you have TB disease.
What can you not do after a TB test?
How do I take care of my arm after the TB skin test?
- Don’t cover the spot with a bandage or tape.
- Be careful not to rub it or scratch it.
- If the spot itches, put a cold cloth on it.
- You can wash your arm and dry it gently.
Is a TB test positive if its red?
The test may be seen as positive if the skin where you were injected is hard, raised, red, and swollen. But redness alone is not considered a positive test result. In many cases, a healthy immune system will surround the TB bacteria soon after you are infected.
Who should not receive a TB skin test?
Recent TB infection (within the past 8 to 10 weeks) Very young age (younger than 6 months) Recent live-virus measles or smallpox vaccination. Incorrect method of giving the TST.
Can you get hives from a TB test?
Some people have an allergic reaction to tuberculin. Seek care immediately if you have any symptoms of allergic reaction, such as hives or swelling.
Does Tuberculosis stay in your system forever?
What is latent TB infection? Many people who have latent TB infection never develop TB disease . In these people, the TB bacteria remain inactive for a lifetime without causing disease . But in other people, especially people who have weak immune systems, the bacteria become active, multiply, and cause TB disease .
Is it normal to have a bump after a TB test?
Your health care provider MUST check your arm 2 or 3 days after the TB skin test, even if your arm looks OK to you. If you have a reaction to the test, it will look like a raised bump. Your health care provider will measure the size of the reaction. If there is a bump, it will go away in a few weeks.
What does a positive TB test look like after 48 hours?
Identifying infection
If you’ve been infected with Mtb, your skin around the site of the injection should start to swell and harden by 48 to 72 hours. This bump, or induration as it’s referred to clinically, will also turn red. The size of the induration, not the redness, is used to determine your results.
What are the side effects of a TB test?
Side effects are uncommon from the Mantoux skin test. However, a person who has been exposed to TB germs may occasionally have a sizable reaction, which may cause some mild itching, swelling or irritation. These kinds of reactions should disappear in one to two weeks.
Can you shower with a TB skin test?
Taking a shower is okay, just be careful not to scrub over the area. What Do the Results Mean? When you come in for your TB skin test read, the medical staff will take a look and feel the area where the test was administered. The medical staff is feeling for a hardened, raised area where the test was administered.
What if my TB test does not bubble?
In most cases, if there is no bump where the testing fluid was placed, you probably are not infected with TB. A doctor or nurse must look at the area to be sure. What if I have a positive TB test? A positive test will look like a raised bump on your arm where the test was placed.
What if your TB test turns red?
Redness alone at the skin test site usually means you have not been infected with TB bacteria. A firm red bump may mean you have been infected with TB bacteria at some time. The size of the firm bump (not the red area) is measured 2 to 3 days after the test to determine the result.
Can you touch a TB test?
It is okay for the test spot to get wet, but do not wipe or scrub the area. Return to the clinic or doctor’s office in 2 to 3 days so your healthcare provider can look at the test spot on your arm.
How many years does a TB test last?
If you have a negative skin test, you need a repeat test at least once every four years. If you have a documented positive skin test, you must have an initial chest X-ray. After that, you still need to be screened every four years.